Classical philosophy and Darwinian biology are far more compatible than is usually assumed. In fact, looking at either from the standpoint of the other can enrich and deepen our appreciation of both. From a Darwinian point of view, the theories of Plato and Aristotle deserve to be taken very seriously. From the classical point of view, Darwinian biology is much less reductionist than its enemies suppose.

Monday, January 28, 2013

Global Warming Leveling Off

I have been blogging about
climate change for several years.My
general view of the issue, stated early on, is as follows:

1.Global warming has been real over the last
century.

2.Human activity may have been a significant factor
in forcing that warming.

3.It is very difficult to tell what the causes of
the warming are and how much of an impact human activity actually had.

4.It is not at all certain whether the effects of
warming have been or will be, on balance, good or bad for human beings.

5.There is no reasonable chance that global
treaties or nation-specific policies will have any impact on human carbon
emissions.

I think I am right on all five
counts.The global treaty initiatives
have come a cropper.Nations committed
to reducing carbon emissions have, for the most part, failed to achieve that
aim.Actual reductions in carbon
emissions have come from economic distress and from the application of new
technologies such as fracking.

After Earth’s mean surface temperature climbed sharply
through the 1990s, the increase has leveled off nearly completely at its 2000
level. Ocean warming also appears to have stabilized somewhat, despite the fact
that CO2 emissions and other anthropogenic factors thought to contribute to
global warming are still on the rise.

This, in scientific terms, is
what counts as a negative finding.Despite increased carbon emissions, warming has leveled off.The Norwegian project used the same framework
as the IPCC.What would be the effect of
doubling carbon emissions from pre-industrial levels?

Uncertainties about the overall results of feedback
mechanisms make it very difficult to predict just how much of the rise in
Earth’s mean surface temperature is due to manmade emissions. According to the
Intergovernmental Panel on Climate Change (IPCC) the climate sensitivity to
doubled atmospheric CO2 levels is probably between 2°C and 4.5°C, with the most
probable being 3°C of warming.

In the Norwegian project, however, researchers have arrived
at an estimate of 1.9°C as the most likely level of warming.

This confirms my points 3, 4,
and 5.We don’t really know how much
human activity is contributing to climate change and we don’t have any good
reason to suppose that the current trajectory of climate change will be
bad.If the Norwegians are right, we
will at worst achieve a level of climate change that the IPCC thought we should
aim at without any help from global treaties.

Climate change should be taken
seriously.Science can tell us a lot but
much of what it tells us is ambiguous.Just
right now, climate change looks to be something less than a crisis.It certainly doesn’t justify hobbling our
economies, which is something we weren’t going to do anyway.